Rahadyan Magetsari

Redesign of Indonesian-made osteosynthesis plates to enhance their mechanical behavior

Mechanical properties determined by fatigue strength, ductility, and toughness are important measures for osteosynthesis plates in order to tolerate some load-bearing situations caused by muscle contractions and weight-bearing effects. Previous study indicated that Indonesian-made plates showed lower mechanical strength compared to the European AO standard plate. High stress under load-bearing situations often starts from surface of the plate; we therefore refined the grain size of the surface by using shot peening and surface mechanical attrition treatment (SMAT). Single cycle bending tests showed that shot-peened and SMAT-treated plates had significantly higher load limit and bending stress compared to the original plates (p<0.05). Weibull analysis confirmed the improvement of proportional load limit of SMAT-treated plates. Fatigue limit also increased upon shot-peening and SMAT treatment (improvement ratio 18% and 27%, respectively). Significant improvement ratio of fatigue tests can be observed in SMAT-treated plates compared to the untreated and shot-peened plates. Fatigue performance demonstrated equivalent results between SMAT-treated and standard plate. These designated that mechanical properties of Indonesian-made plates can be improved upon SMAT treatment leading to significant enhancement of mechanical strength thus is comparable to the standard plate. Our findings highlight the benefits of SMAT treatment to improve mechanical strength of Indonesian-made osteosynthesis plates.

Mechanical properties of Indonesian-made narrow dynamic compression plate.

Osteosynthesis plates are clinically used to fixate and position a fractured bone. They should have the ability to withstand cyclic loads produced by muscle contractions and total body weight. The very high demand for osteosynthesis plates in developing countries in general and in Indonesia in particular necessitates the utilisation of local products. In this paper, we investigated the mechanical properties, i.e. proportional limit and fatigue strength of Indonesian-made Narrow Dynamic Compression Plates (Narrow DCP) as one of the most frequently used osteosynthesis plates, in comparison to the European AO standard plate, and its relationship to geometry, micro structural features and surface defects of the plates. All Indonesian-made plates appeared to be weaker than the standard Narrow DCP because they consistently failed at lower stresses. Surface defects did not play a major role in this, although the polishing of the Indonesian Narrow DCP was found to be poor. The standard plate showed indications of cold deformation from the production process in contrast to the Indonesian plates, which might be the first reason for the differences in strength. This is confirmed by hardness measurements. A second reason could be the use of an inferior version of stainless steel. The Indonesian plates showed lower mechanical behaviour compared to the AO-plates. These findings could initiate the development of improved Indonesian manufactured DCP-plates with properties comparable to commonly used plates, such as the standard European AO-plates.

Three Dimensional Morphometry of Distal Femur to Design Knee Prosthesis for Indonesian Population

El objetivo fue disenar una protesis a medida para una determinada poblacion, por tanto la morfometria debia ser medida para proporcionar datos basicos para disenar el tamano ideal de una protesis total para la artroplastia de rodilla en poblacion de Indonesia. Se realizo un estudio antropometrico sobre 100 sujetos sanos indonesios, basados en tomografias computadorizadas (TC) de la superficie resecada del femur distal. Los parametros que se midieron fueron longitud femoral mediolateral (FML), longitud femoral anteroposterior (FAP), longitud femoral medial anteroposterior (FMAP), longitud femoral lateral anteroposterior (FLAP), y razon de aspecto femoral (FR). Las medias FAP y FML fueron 54,60±5,71 y 65,98±6,51, respectivamente. La morfometria del femur distal fue significativamente diferente entre hombres y mujeres (mayor tamano en hombres), sin embargo uno de los parametros mostro resultados diferentes, la FLAP. Las personas indonesias son de menor tamano en comparacion con su contraparte occidental. Las dimensiones propuestas se pueden utilizar como los datos basicos para disenar el tamano ideal para una protesis de rodilla a medida para la poblacion de Indonesia.

Three Dimensional Morphometry of Proximal Femur to Design Best-Fit Femoral Stem for Indonesian Population

Para disenar protesis a medida en una poblacion determinada, la morfometria necesita ser conocida. El objetivo de este estudio fue obtener resultados que sean utiles en la investigacion para disenar el tamano ideal de una protesis total de artroplastia de cadera para la poblacion de Indonesia. Fue realizado un estudio antropometrico en 100 sujetos sanos de raza mongoloide de Indonesia, en los que se estudio la parte proximal del femur por tomografia computadorizada (TC). Se consideraron como parametros la cabeza del femur (CF), posicion de la cabeza del femur (PCF), diametro de la cabeza del femur (DCF), angulo cervicodiafisario (ACD), ancho anteroposterior (AAP) y ancho-lateral en 3 lugares diferentes. La poblacion Indonesia tiene una morfometria menor del femur proximal en comparacion con la poblacion occidental. El valor medio de todos los parametros en hombres fueron mayores a las mujeres. Por otra parte, CF y PCF mostraron diferencia significativa entre hombres y mujeres e indico una ubicacion superior del centro de la cabeza del femur en hombres, en comparacion con las mujeres. Se encontro que la dimension del canal femoral fue mediolateral oval, 1,43, 1,28, y 1,34, en 3 cortes diferentes, respectivamente (20 mm superior y 40 mm inferior del trocanter menor e istmo). La dimension del femur proximal en la poblacion de Indonesia es de menor tamano en comparacion con la contraparte occidental. Las dimensiones propuestas se pueden utilizar como datos basicos para el diseno de un tamano ideal de vastago femoral para la poblacion Indonesia.

Pin on flat wear volume prediction of UHMWPE against cp Ti for orthopedic applications

Tribological assessment of orthopedic biomaterials requires a lot of testing time. Researchers must test the biomaterials in millions of cycles at low frequency (1 Hz) to mimic the in vivo conditions. It is a problem because product designs and developments could not wait longer for wear data to predict the lifetime of their products. The problem can be solved with the use of computation techniques to model the wear phenomena and provide predicted data. The aim of this research is to predict the wear volume of the commonly used ultra high molecular weight polyethylene (UHMWPE) sliding against commercially pure titanium (cp Ti) in the unidirectional pin on flat tests. The 9 mm diameter UHMWPE pin and cp Ti plate contact mechanics were modeled using Abaqus. Contact pressure was set at 3 MPa. Outputs of the computations (contact pressure and contact area) were used to calculate the wear volume with Archard law. A custom Python script was made to automate the process. The results were then compared with experimental data for validations. The predicted data were in a good trend with numerical errors from 0.3% up to 26%.

Drop hand treated with modified jones transfer

Introduction: The radial nerve is the most frequently injured nerve caused by fractures of the humeral shaft. Loss of hand function secondary to radial nerve injury can dramatically impair the person’s ability to perform normal activities of daily living. When nerve repair is not possible or the window of opportunity for nerve repair is missed, tendon transfers can be done to restore lost functions. Case Series: There were 2 cases of drop hand, the first patient was male, 30-year-old with close fracture of middle third of the right humerus with radial nerve palsy due to motorcycle accident. From electroneuromyography (ENMG) examination the nerve lesion was said to be a neurotmesis. The patient underwent open reduction followed with plating of the humeral fracture, and nerve repair. After six months, the drop hand still remain and then the patient underwent tendon transfer (Jones procedure); palmaris longus (PL) transferred to extensor policis longus (EPL), pronator teres (PT) transferred to extensor carpi radialis brevis (ECRB), flexor carpi radialis (FCR) transferred to extensor digitorumcomunis (EDC). Second patient was male 28-year-old with close fracture of middle third of the right humerus with neurotmesis of radial nerve due to motorcycle accident. The patient underwent open reduction, plating Meirizal1, Sudaryanto1, Rahadyan Magetsari1 Affiliations: 1Department of Orthopedics and Traumatology, Sardjito General Hospital, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia. Corresponding Author: Sudaryanto, Department of Orthopedics and Traumatology, Sardjito General Hospital, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia; Email: sudaryantoku06@gmail.com Received: 18 April 2018 Accepted: 23 May 2018 Published: 22 June 2018 of humeral fracture, and nerve repair. After five months follow up drop hand still remain then underwent tendon transfer (modified Jones procedure); PL transferred to EPL, FCR transferred to EDC and ECRL. There was good result after operation of the patient with tendon transfers. Both patients can extend wrist, extend the finger and extend the thumb. Conclusion: Both patients with Radial nerve palsy treated with tendon transfers showed good clinical results and improvement of the hand function.

Post functional reconstruction of modified pollicization technique and posterior interosseous artery flap in primary bone NHL of the hand: A rare case report

Introduction: Primary Non Hodgkin Lymphoma (NHL) of the bone is rare malignancy accounting less than 1–2% of adult NHL and less than 7–10% of primary bone tumors. Most primary bone lymphomas are NHL with diffuse large b-cell subtype. It is frequently misdiagnosed due to its rarity, uncommon presentation and indistinctive radiographic features. case report: A 40-year-old man presented with the left 2nd metacarpal tumor complained of pain, swelling with difficulty in both active and passive movements. the diagnosis of bone NHL established from clinical finding, radiographic examination and biopsy. Immunohistochemical result showed positivity of LcA and cD20, with high proliferation index of Ki-67, suggesting b-cell lineage of lymphoma. Functional hand reconstruction with modified pollicization technique and posterior interosseous artery flap were performed. the follow-up for the possibility of a local tumour recurrence and Rahadyan Magetsari1, Aditya Fuad Robby Triangga2, EryKus Dwianingsih3, Meirizal1 Affiliations: 1Staff of Orthopaedic & Traumatology Departement, Gadjah Mada University, Sardjito Hospital, Yogyakarta; 2Resident of Orthopaedic & Traumatology Departement, GadjahMada University, Sardjito Hospital, Yogyakarta; 3Staff of Anatomy Pathology Department, GadjahMada University, Sardjito Hospital, Yogyakarta. Corresponding Author: Aditya Fuad Robby Triangga, MD, Resident of Orthopaedic & Traumatology Departement, Gadjah Mada University, Sardjito Hospital, Yogyakarta, Indonesia; Email: dr.robby_triangga@yahoo.com Received: 21 March 2018 Accepted: 17 April 2018 Published: 01 May 2018 metastasis was evaluated after 8 courses of rcHOP regiment chemotherapy. conclusion: Primary NHL of the bone especially in hand is very rare and challenging condition for orthopaedic surgeons. the triple diagnosis of clinical, radiographic and biopsy examinations were very useful to establish solid diagnosis of bone NHL. therefore, prognosis, nonetheless, is much better than that of other malignant bone tumours. Awareness and knowledge in decision making of hand reconstruction and post-operative chemotherapy planning are needed to achieve statisfactory outcome.

Increasing Yield Strength of AISI 316L Plastically Deformed by Expanded Hole Techniques

AISI 316L has been used to produce implant plates such as dynamic copmresion plates (DCP). The implant plates might experienced failure due to either suffer higher stresses exceeding the allowable maximum strenght or presents small crack growing through fatigue mechanism. Most of DCP fractures occured at the gliding holes region. This study conducted improving strength of DCP locally on the gliding holes. Strengthening on the gliding holes of DCP was performed by cold working method involving plastically deformation using an expanded hole technique. This study was conducted by both experimental and numerical simulation. Increasing strength locally on the gliding hole region was evaluated by measuring some parameters incorporated with strain hardening mechanism such as hardness and residual stresses. Increasing yields strength locally on the hole region was estimated by Takakuwa’s formulas. By this method, yields strength of the gliding hole of DCP made of AISI 316L increased from 325 MPa to be 600−1050 MPa.

Development of the Gliding Hole of the Dynamics Compression Plate

The gliding hole of the dynamics compression plate is designed to facilitate relative movement of pedicle screw during surgery application. The gliding hole shape is then geometrically complex. The gliding hole manufactured using machining processes used to employ ball-nose cutting tool. Then, production cost is expensive due to long production time. This study proposed to increase productivity of DCP products by introducing forming process (cold forming). The forming process used to involve any press tool devices. In the closed die forming press tool is designed with little allowance, then work-pieces is trapped in the mould after forming. Therefore, it is very important to determine hole geometry and dimensions of raw material in order to success on forming process. This study optimized the hole sizes with both geometry analytics and experiments. The success of the forming process was performed by increasing the holes size on the raw materials. The holes size need to be prepared is diameter of 5.5 mm with a length of 11.4 mm for the plate thickness 3 mm and diameter of 6 mm with a length of 12.5 mm for the plate thickness 4 mm.

Functional Outcome of Galeazzi Fractures Treated by ORIF and DRUJ Stabilization either Using Long Arm Cast or Transfixing Wire

Introduction: Galeazzi fracture is a condition where there is distal radial shaft fracture accompanied with disruption of the Distal Radioulnar Joint (DRUJ). Assessment of distal radio ulnar joint stability is mandatory and followed by further joint stabilization methods. The aim of this study was to study the functional outcome Galeazzi fracture management treated with ORIF followed by DRUJ strabilization using transfixing wire with long arm splint compared with long arm cast. Materials and methods: This study was a cross sectional observational study in patients with Galeazzi fractures from January 2007 to May 2012 underwent ORIF and DRUJ stabilization either using long arm cast or transfixing wire and long arm splint. Functional outcome measurement started at 3 months after surgery. The researcher contacted those eligible patients. After patients gave consent to the study, they were asked to do an interview guided by the researcher using QuickDASH score. The data was analysed using Fisher Exact test. Results: A total of 32 patients with Galeazzi fracture underwent ORIF followed by DRUJ stabilization. 72% had good functional outcome in subjects underwent ORIF followed by transfixing wire with long arm splint and 79% subjects using long arm cast (p-value>0.05). Conclusion: This study showed that Galeazzi fracture patients treated with ORIF followed by long arm cast or transfixing wire and long arm splint had not significantly differ and had equally good functional outcome results.